A catalyst for hydrogenation of cyclohexane dicarboxylic acid ester and its preparation and application

Abstract

The application discloses a catalyst for preparing cyclohexane dicarboxylic ester by hydrogenating terephthalic acid ester and a preparation method and application thereof. The catalyst comprises the following components in parts by weight: a) 0.1-35 parts of an active component, which comprises Ru in terms of elements; b) 1-50 parts of an auxiliary component, which comprises one or more of Pd, Cu, Zn, Mn, Co, K and Ca in terms of elements; and c) 15-98 parts of a carrier; wherein the H2-TPR main reduction peak position of the catalyst is 100-150 DEG C. When the catalyst is used for preparing cyclohexane dicarboxylic ester by hydrogenating terephthalic acid ester, the conversion rate of raw materials under low-temperature conditions can be improved.

Description

Technical Field

[0001] This invention belongs to the field of cyclohexane dicarboxylic acid ester preparation, specifically relating to a catalyst for the hydrogenation of terephthalic acid ester to cyclohexane dicarboxylic acid ester, its preparation method, and its application. Background Technology

[0002] Dimethyl 1,4-cyclohexanedicarboxylate (DMCD) is an important chemical intermediate that can be hydrogenated to prepare 1,4-cyclohexanediethanol (CHDM). CHDM is a crucial intermediate used in the synthesis of various high-performance polyester materials (PETG, PCT, PCTG, etc.). With the development of the downstream polyester industry, the demand for CHDM in the Chinese market will continue to increase in the future, and the demand for DMCD, as an intermediate in the preparation of CHDM, will also increase accordingly.

[0003] Currently, the world's major producers and patent holders of 1,4-cyclohexanediethanol (DMCD) include Eastman Chemical Company of the United States, Mitsubishi Chemical of Japan, and SK Chemicals of South Korea. Among them, Eastman Chemical Company is the largest producer, with DMCD production facilities in the United States, Switzerland, and other locations. In 1959, Eastman Chemical Company of the United States first used dimethyl terephthalate (DMT) as a raw material to selectively hydrogenate DMCD, which is also the only process route that has been industrialized to date.

[0004] CN1099745A and CN1058959C disclose a low-pressure method for producing dimethyl 1,4-cyclohexanedicarboxylate (DMCD) by hydrogenation of dimethyl terephthalate (DMT). In the presence of a Pd / Al₂O₃ catalyst, a mixed liquid containing DMT and DMCD (DMT / DMCD = 3:7, by weight) is continuously fed into a fixed-bed reactor and reacted with hydrogen. The reaction is carried out at a pressure of 4 MPa, a temperature of 160–220 °C, and a liquid hourly space velocity of 0.5–2 h⁻¹. -1 The process is carried out under the aforementioned conditions. The patent specifically mentions that the low-pressure hydrogenation process (<17.5 MPa) generates CO gas, which reduces the activity of Pd-based catalysts. The tolerance concentration of CO gas for heavy metal catalysts such as Pd is 500 ppmv, preferably 100 ppmv. To limit the impact of carbon monoxide on catalyst activity, the above method discharges CO-containing purge hydrogen gas at a rate of 8–10 L / min, thereby reducing the carbon monoxide content in the reaction system. However, directly discharging hydrogen gas leads to increased costs, and cryogenic or pressure swing adsorption (PSA) treatment of the hydrogen effluent would increase energy consumption and processing costs. Summary of the Invention

[0005] To address the problem of low conversion rates of dimethyl terephthalate to dimethyl 1,4-cyclohexanedicarboxylate under low-temperature conditions in existing technologies, this invention provides a novel catalyst for the hydrogenation of terephthalic acid esters to cyclohexanedicarboxylate, along with its preparation method and applications. The catalyst of this invention exhibits high dimethyl terephthalate conversion rates under low-temperature conditions when used for the hydrogenation of terephthalic acid esters to cyclohexanedicarboxylate.

[0006] The first aspect of the present invention provides a catalyst for the hydrogenation of terephthalic acid ester to cyclohexane dicarboxylic acid ester, comprising, by weight, the following components:

[0007] a) 0.1-35 parts of the active ingredient, calculated by element, wherein the active ingredient includes Ru;

[0008] b) 1-50 parts of the auxiliary component, which, based on elements, includes one or more of Pd, Cu, Zn, Mn, Co, K, and Ca;

[0009] c) 15-98 copies of the vector;

[0010] The main reduction peak of the catalyst, H2-TPR, is located at 100-150℃.

[0011] Furthermore, the main reduction peak of the catalyst in H2-TPR is located at 100-120℃.

[0012] Furthermore, in the catalyst, the average particle size of Ru crystals is 2-4 nm.

[0013] Furthermore, the auxiliary component preferably includes one or more of Co, Mn, and Ca.

[0014] Furthermore, the auxiliary component preferably includes Co, Mn, and Ca simultaneously, wherein the weight ratio of Co, Mn, and Ca, based on elemental composition, is (1-4):(3-8):10, preferably (2-3):(4-6):10. This invention, through the synergistic effect of Co, Mn, and Ca, achieves high conversion rate of dimethyl terephthalate under low-temperature conditions, demonstrating outstanding performance.

[0015] Furthermore, the content of the active component is preferably 0.2-20 parts by weight, more preferably 0.5-10 parts, for example but not limited to: 0.5 parts, 1 part, 2 parts, 4 parts, 6 parts, 8 parts, 10 parts, etc.

[0016] Furthermore, the content of the auxiliary component is preferably 2-40 parts by weight, more preferably 4-30 parts, and examples, but not limited to: 4 parts, 5 parts, 6 parts, 8 parts, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, etc.

[0017] Furthermore, the carrier content is preferably 40-96 parts by weight, more preferably 60-94 parts.

[0018] Furthermore, in the catalyst, the active component exists in the form of ruthenium hydroxide and / or ruthenium oxide, and the auxiliary element exists in the catalyst in the form of oxide.

[0019] Furthermore, the carrier is selected from at least one of alumina, silicon dioxide, and molecular sieves, preferably alumina.

[0020] A second aspect of the present invention provides a method for preparing the above-mentioned catalyst for the hydrogenation of p-phenylene dicarboxylate to cyclohexane dicarboxylate, comprising the following steps:

[0021] 1) The auxiliary agent source solution and the carrier are brought into contact for the first time, and then aged, dried and calcined to obtain the modified carrier;

[0022] 2) Add the modified support obtained in step 1) to a Ru-containing solution, then add a precipitant solution for a second contact, age, filter, and dry to obtain the catalyst.

[0023] Furthermore, in step 2), the endpoint pH value of the second contact system is controlled to be 6.0-8.0, preferably 7.0-8.0.

[0024] Furthermore, in step 1), the aging temperature is 15–60°C, and the aging time is 1–24 hours.

[0025] Furthermore, in step 2), the aging temperature is 15–50°C, and the aging time is 1–24 hours.

[0026] Further, in step 1), the auxiliary agent source is selected from one or more of H2PdCl4, PdCl2, Cu(NO3)2, Zn(NO3)2, Mn(NO3)2, KNO3, Co(NO3)2, and Ca(NO3)2, preferably selected from one or more of Co(NO3)2, Mn(NO3)2, and Ca(NO3)2.

[0027] Further, in step 1), the auxiliary agent source can be a salt hydrate, such as one or more of Cu(NO3)2·3H2O, Zn(NO3)2·6H2O, Mg(NO3)2·6H2O and Ca(NO3)2·4H2O.

[0028] Furthermore, the first contact between the auxiliary agent source solution and the carrier in step 1) can be achieved by an equal-volume impregnation method.

[0029] Further, the precipitant in step 2) is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate and ammonia water, preferably potassium hydroxide and / or ammonia water.

[0030] Further, in step 2), the Ru source in the Ru-containing solution is at least one of ruthenium chloride, ruthenium chloride, and ruthenium chloride salt, preferably ruthenium chloride.

[0031] Further, in step 1), the concentration of the auxiliary agent source solution is 0.1-3.0 mol / L, preferably 0.3-2.0 mol / L.

[0032] Further, in step 2), the concentration of the precipitant solution is 0.1-3.0 mol / L.

[0033] Further, in step 1), the concentration of the Ru-containing solution is 0.1-5.0 mol / L, preferably 0.5-4.0 mol / L. Further, in step 1), the calcination is carried out in an air atmosphere.

[0034] Further, in step 1), the calcination temperature is 300-1000℃ and the calcination time is 2-8h, preferably the calcination temperature is 400-800℃ and the calcination time is 4-6h.

[0035] Further, in step 1), the drying temperature is 70-130℃ and the time is 3-24h, preferably the drying temperature is 90-120℃ and the time is 8-15h.

[0036] Further, in step 2), the drying temperature is 50-140℃ and the time is 3-24h, preferably the drying temperature is 80-120℃ and the time is 8-15h.

[0037] A third aspect of the present invention provides a method for hydrogenating terephthalic acid ester to cyclohexane dicarboxylate, comprising reacting terephthalic acid ester with hydrogen gas in the presence of a catalyst as described in the first aspect of the present invention or a catalyst prepared according to the method described in the second aspect of the present invention to generate cyclohexane dicarboxylate.

[0038] Furthermore, the temperature at which the terephthalic acid ester reacts with hydrogen is 100-230°C, preferably 130-200°C.

[0039] Furthermore, the pressure at which the terephthalic acid ester reacts with hydrogen is 4.0-15.0 MPa, preferably 6.0-13.0 MPa.

[0040] Furthermore, the liquid hourly space velocity (LHSV) of the reaction between the terephthalic acid ester and hydrogen is 0.5-12 h⁻¹. -1 Preferably 2-8 hours-1 .

[0041] Furthermore, the molar ratio of hydrogen to terephthalic acid ester in the reaction of terephthalic acid ester with hydrogen gas is 5:1-200:1, preferably 20:1-80:1.

[0042] Furthermore, the dimethyl terephthalate is typically dissolved in dimethyl 1,4-cyclohexanedicarboxylate, i.e., a dimethyl terephthalate solution. The mass content of dimethyl terephthalate is 2% to 10%.

[0043] Compared with the prior art, the present invention has the following advantages:

[0044] This invention provides a catalyst for the hydrogenation of diphenylcarboxylic acid esters to prepare cyclohexanedicarboxylic acid esters (especially the hydrogenation of dimethyl terephthalate to prepare dimethyl 1,4-cyclohexanedicarboxylic acid ester), which has the characteristics of a low reduction peak position and suitable crystal size, and can improve the conversion rate of raw materials under low temperature conditions. Attached Figure Description

[0045] Figure 1 The above are H2-TPR diagrams of the catalysts prepared in Example 1 and Comparative Example 1.

[0046] Figure 2 Transmission electron microscopy (TEM) images of the catalysts prepared in Example 1 and Comparative Example 1;

[0047] Wherein, A - Comparative Example 1, B - Example 1. Detailed Implementation

[0048] To make the present invention easier to understand, it will be described in detail below with reference to embodiments and accompanying drawings. These embodiments are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used that do not specify the manufacturer are products that can be obtained commercially or using conventional methods.

[0049] In this invention, a temperature-programmed reduction analysis (H2-TPR) instrument is used to test the redox properties of the catalyst. In the H2-TPR graph, the horizontal axis represents temperature, which represents the H2 reduction temperature of Ru compound in the catalyst. The magnitude of the temperature represents the different reduction properties of the catalyst. The vertical axis represents %TCD, with the unit being au (any unit, dimensionless), which represents the hydrogen consumption index.

[0050] In this invention, the conversion rate and selectivity of dimethyl terephthalate to dimethyl 1,4-cyclohexanedicarboxylate are calculated using the following formulas:

[0051]

[0052]

[0053] In the formula: n - amount of substance, in mol; DMT - dimethyl terephthalate; DMCD - dimethyl 1,4-cyclohexanedicarboxylate; 1 - raw material; 2 - product.

[0054] In the following examples and comparative examples, the dimethyl terephthalate used was industrial grade, dissolved in dimethyl 1,4-cyclohexanedicarboxylate, i.e., a dimethyl terephthalate solution, wherein the mass fraction of dimethyl terephthalate was 4% and the mass fraction of dimethyl 1,4-cyclohexanedicarboxylate was 96%. The hydrogen gas used had a volume fraction of 99.9%.

[0055] Example 1

[0056] 1) Catalyst preparation:

[0057] The first step is the preparation of the modified carrier. The specific steps are as follows: (a) Co(NO3)2, Mn(NO3)2 and Ca(NO3)2 are prepared into a solution I with a concentration of 0.8 mol / L by a weight ratio of 2:5:10 based on the elements Co, Mn and Ca. (b) Using the equal volume impregnation method, 12 g of alumina carrier is added to the solution containing the auxiliary salts for the first contact. The mixture is stirred evenly, aged at 25°C for 5 hours, dried at 120°C for 12 hours, and calcined at 600°C for 4 hours to obtain the modified alumina.

[0058] The next step is to prepare the catalyst by precipitation of the active components. The specific steps are as follows: (c) Ruthenium chloride is prepared into a 0.8 mol / L solution II; (d) potassium hydroxide, the precipitant, is prepared into a 1.0 mol / L solution III; (e) the modified alumina support is added to solution II containing Ru salt, followed by solution III for a second contact. The pH value at the endpoint is controlled to be 7.5. The catalyst is aged at 25°C for 4 hours, filtered, washed, and then dried at 110°C for 12 hours to obtain the final catalyst product. The obtained catalyst contains 2% Ru, 0.6% Co, 1.5% Mn, and 3% Ca by mass.

[0059] Figure 2 B is a transmission electron microscope (TEM) image of the catalyst prepared in Example 1, with an average Ru grain size of 2.2 nm.

[0060] 2) Catalyst reduction:

[0061] 10g of catalyst, 20mL of catalyst loading, pure hydrogen gas, reduction at 200℃ for 10h.

[0062] 3) Catalytic hydrogenation:

[0063] Using dimethyl terephthalate solution and pure hydrogen as raw materials, with a catalyst dosage of 10 g, the reaction was carried out at a temperature of 150℃, a reaction pressure of 7.0 MPa, a hydrogen / dimethyl terephthalate molar ratio of 30:1, and a liquid hourly space velocity of 3.0 h⁻¹. -1 Hydrogenation experiments were conducted under the specified conditions, and the reaction results are shown in Table 1. The DMT conversion rate was 99.9%, and the DMCD selectivity was 97.9%.

[0064] Example 2

[0065] The catalyst in this embodiment was prepared using the same method as the catalyst in Example 1, with the only difference being that the weight ratio of the auxiliary salts Co(NO3)2, Mn(NO3)2, and Ca(NO3)2, calculated as elemental Co, Mn, and Ca, was 2:6:10. In the resulting catalyst, the mass content of Ru was 2%, the mass content of Co was 0.6%, the mass content of Mn was 1.8%, and the mass content of Ca was 3%.

[0066] The transmission electron microscope (TEM) images show that the average Ru grain size is 3.1 nm.

[0067] 1) Catalyst reduction:

[0068] 10g of catalyst, 20mL of catalyst loading, pure hydrogen gas, reduction at 200℃ for 10h.

[0069] 2) Catalytic hydrogenation:

[0070] Using dimethyl terephthalate solution and pure hydrogen as raw materials, with a catalyst dosage of 10 g, the reaction was carried out at a temperature of 150℃, a reaction pressure of 7.0 MPa, a hydrogen / dimethyl terephthalate molar ratio of 30:1, and a liquid hourly space velocity of 3.0 h⁻¹. -1 Hydrogenation experiments were conducted under the specified conditions, and the reaction results are shown in Table 1. The DMT conversion rate was 99.7%, and the DMCD selectivity was 97.6%.

[0071] Example 3

[0072] The catalyst in this embodiment was prepared using the same method as the catalyst in Example 1, with the only difference being that the weight ratio of the auxiliary salts Co(NO3)2, Mn(NO3)2, and Ca(NO3)2, calculated as elemental Co, Mn, and Ca, was 2:3:10. In the resulting catalyst, the mass content of Ru was 2%, the mass content of Co was 0.6%, the mass content of Mn was 0.9%, and the mass content of Ca was 3%.

[0073] The transmission electron microscope (TEM) images show that the average Ru grain size is 3.3 nm.

[0074] 1) Catalyst reduction:

[0075] 10g of catalyst, 20mL of catalyst loading, pure hydrogen gas, reduction at 200℃ for 10h.

[0076] 2) Catalytic hydrogenation:

[0077] Using dimethyl terephthalate solution and pure hydrogen as raw materials, with a catalyst dosage of 10 g, the reaction was carried out at a temperature of 150℃, a reaction pressure of 7.0 MPa, a hydrogen / dimethyl terephthalate molar ratio of 30:1, and a liquid hourly space velocity of 3.0 h⁻¹. -1 Hydrogenation experiments were conducted under the specified conditions, and the reaction results are shown in Table 1. The DMT conversion rate was 99.0%, and the DMCD selectivity was 97.4%.

[0078] Example 4

[0079] The catalyst in this embodiment was prepared using the same method as the catalyst in Example 1, except that Ca was not added. The resulting catalyst contained 2% Ru by mass, 0.6% Co by mass, and 1.5% Mn by mass.

[0080] The transmission electron microscope (TEM) images show that the average Ru grain size is 3 nm.

[0081] 1) Catalyst reduction:

[0082] 10g of catalyst, 20mL of catalyst loading, pure hydrogen gas, reduction at 200℃ for 10h.

[0083] 2) Catalytic hydrogenation:

[0084] Using dimethyl terephthalate solution and pure hydrogen as raw materials, with a catalyst dosage of 10 g, the reaction was carried out at a temperature of 150℃, a reaction pressure of 7.0 MPa, a hydrogen / dimethyl terephthalate molar ratio of 30:1, and a liquid hourly space velocity of 3.0 h⁻¹. -1 Hydrogenation experiments were conducted under the specified conditions, and the reaction results are shown in Table 1. The DMT conversion rate was 98.4%, and the DMCD selectivity was 96.9%.

[0085] Example 5

[0086] The catalyst in this embodiment was prepared using the same method as the catalyst in Example 1, except that Co was not added. The resulting catalyst contained 2% Ru, 1.5% Mn, and 3% Ca by mass.

[0087] The transmission electron microscope (TEM) images show that the average Ru grain size is 2.5 nm.

[0088] 1) Catalyst reduction:

[0089] 10g of catalyst, 20mL of catalyst loading, pure hydrogen gas, reduction at 200℃ for 10h.

[0090] 2) Catalytic hydrogenation:

[0091] Using dimethyl terephthalate solution and pure hydrogen as raw materials, with a catalyst dosage of 10 g, the reaction was carried out at a temperature of 150℃, a reaction pressure of 7.0 MPa, a hydrogen / dimethyl terephthalate molar ratio of 30:1, and a liquid hourly space velocity of 3.0 h⁻¹. -1 Hydrogenation experiments were conducted under the specified conditions, and the reaction results are shown in Table 1. The DMT conversion rate was 99.2%, and the DMCD selectivity was 97.3%.

[0092] Example 6

[0093] The catalyst in this embodiment was prepared using the same method as the catalyst in Example 1, with the only difference being that the precipitant used in the second contact was a sodium hydroxide solution with a concentration of 0.1 mol / L.

[0094] The transmission electron microscope (TEM) images show that the Ru grain size is 2.3 nm.

[0095] 1) Catalyst reduction:

[0096] 10g of catalyst, 20mL of catalyst loading, pure hydrogen gas, reduction at 200℃ for 10h.

[0097] 2) Catalytic hydrogenation:

[0098] Using dimethyl terephthalate solution and pure hydrogen as raw materials, with a catalyst dosage of 10 g, the reaction was carried out at a temperature of 150℃, a reaction pressure of 7.0 MPa, a hydrogen / dimethyl terephthalate molar ratio of 30:1, and a liquid hourly space velocity of 3.0 h⁻¹. -1 Hydrogenation experiments were conducted under the specified conditions, and the reaction results are shown in Table 1. The DMT conversion rate was 99.6%, and the DMCD selectivity was 97.7%.

[0099] Example 7

[0100] The catalyst in this embodiment was prepared using the same method as the catalyst in Example 1, with the only difference being the different auxiliary agents used. In the resulting catalyst, the mass content of Ru was 2%, the mass content of Mn was 1.5%, and the mass content of Zn was 5%.

[0101] The transmission electron microscope (TEM) images show that the average Ru grain size is 3.4 nm.

[0102] 1) Catalyst reduction:

[0103] 10g of catalyst, 20mL of catalyst loading, pure hydrogen gas, reduction at 200℃ for 10h.

[0104] 2) Catalytic hydrogenation:

[0105] Using dimethyl terephthalate solution and pure hydrogen as raw materials, with a catalyst dosage of 10 g, the reaction was carried out at a temperature of 150℃, a reaction pressure of 7.0 MPa, a hydrogen / dimethyl terephthalate molar ratio of 30:1, and a liquid hourly space velocity of 3.0 h⁻¹. -1 Hydrogenation experiments were conducted under the specified conditions, and the reaction results are shown in Table 1. The DMT conversion rate was 97.1%, and the DMCD selectivity was 96.8%.

[0106] Example 8

[0107] The catalyst in this embodiment was prepared using the same method as the catalyst in Example 1, with the only difference being that the final pH value of the second contact system was 7.1.

[0108] The transmission electron microscope (TEM) images show that the average Ru grain size is 2.4 nm.

[0109] 1) Catalyst reduction:

[0110] 10g of catalyst, 20mL of catalyst loading, pure hydrogen gas, reduction at 200℃ for 10h.

[0111] 2) Catalytic hydrogenation:

[0112] Using dimethyl terephthalate solution and pure hydrogen as raw materials, with a catalyst dosage of 10 g, the reaction was carried out at a temperature of 150℃, a reaction pressure of 7.0 MPa, a hydrogen / dimethyl terephthalate molar ratio of 30:1, and a liquid hourly space velocity of 3.0 h⁻¹. -1 Hydrogenation experiments were conducted under the specified conditions, and the reaction results are shown in Table 1. The DMT conversion rate was 99.4%, and the DMCD selectivity was 97.5%.

[0113] Example 9

[0114] The catalyst in this embodiment was prepared using the same method as the catalyst in Example 1, with the only difference being that the aging time after the first contact was 18 hours.

[0115] The transmission electron microscope (TEM) images show that the average Ru grain size is 2.25 nm.

[0116] 1) Catalyst reduction:

[0117] 10g of catalyst, 20mL of catalyst loading, pure hydrogen gas, reduction at 200℃ for 10h.

[0118] 2) Catalytic hydrogenation:

[0119] Using dimethyl terephthalate solution and pure hydrogen as raw materials, with a catalyst dosage of 10 g, the reaction was carried out at a temperature of 150℃, a reaction pressure of 7.0 MPa, a hydrogen / dimethyl terephthalate molar ratio of 30:1, and a liquid hourly space velocity of 3.0 h⁻¹. -1 Hydrogenation experiments were conducted under the specified conditions, and the reaction results are shown in Table 1. The DMT conversion rate was 99.9%, and the DMCD selectivity was 97.8%.

[0120] Example 10

[0121] The catalyst in this embodiment was prepared using the same method as the catalyst in Example 1, with the only difference being that the aging time after the second contact was 18 hours.

[0122] The transmission electron microscope (TEM) images show that the average Ru grain size is 2.3 nm.

[0123] 1) Catalyst reduction:

[0124] 10g of catalyst, 20mL of catalyst loading, pure hydrogen gas, reduction at 200℃ for 10h.

[0125] 2) Catalytic hydrogenation:

[0126] Using dimethyl terephthalate solution and pure hydrogen as raw materials, with a catalyst dosage of 10 g, the reaction was carried out at a temperature of 150℃, a reaction pressure of 7.0 MPa, a hydrogen / dimethyl terephthalate molar ratio of 30:1, and a liquid hourly space velocity of 3.0 h⁻¹. -1 Hydrogenation experiments were conducted under the specified conditions, and the reaction results are shown in Table 1. The DMT conversion rate was 99.7%, and the DMCD selectivity was 97.8%.

[0127] Example 11

[0128] The catalyst and preparation method in this embodiment are the same as those in Example 1.

[0129] 1) Catalyst reduction:

[0130] 10g of catalyst, 20mL of catalyst loading, pure hydrogen gas, reduction at 200℃ for 10h.

[0131] 2) Catalytic hydrogenation:

[0132] Using dimethyl terephthalate solution and pure hydrogen as raw materials, with a catalyst dosage of 10 g, the reaction was carried out at a temperature of 140℃, a reaction pressure of 7.0 MPa, a hydrogen / dimethyl terephthalate molar ratio of 30:1, and a liquid hourly space velocity of 3.0 h⁻¹. -1 Hydrogenation experiments were conducted under the specified conditions, and the reaction results are shown in Table 1. The DMT conversion rate was 99.8%, and the DMCD selectivity was 98.0%.

[0133] Example 12

[0134] The catalyst and preparation method in this embodiment are the same as those in Example 1.

[0135] 1) Catalyst reduction:

[0136] 10g of catalyst, 20mL of catalyst loading, pure hydrogen gas, reduction at 200℃ for 10h.

[0137] 2) Catalytic hydrogenation:

[0138] Using dimethyl terephthalate solution and pure hydrogen as raw materials, with a catalyst dosage of 10 g, the reaction was carried out at a temperature of 150℃, a reaction pressure of 6.0 MPa, a hydrogen / dimethyl terephthalate molar ratio of 30:1, and a liquid hourly space velocity of 3.0 h⁻¹. -1 Hydrogenation experiments were conducted under the specified conditions, and the reaction results are shown in Table 1. The DMT conversion rate was 99.5%, and the DMCD selectivity was 97.7%.

[0139] Example 13

[0140] The catalyst and preparation method in this embodiment are the same as those in Example 1.

[0141] 1) Catalyst reduction:

[0142] 10g of catalyst, 20mL of catalyst loading, pure hydrogen gas, reduction at 200℃ for 10h.

[0143] 2) Catalytic hydrogenation:

[0144] Using dimethyl terephthalate solution and pure hydrogen as raw materials, with a catalyst dosage of 10 g, the reaction was carried out at a temperature of 150℃, a reaction pressure of 7.0 MPa, a hydrogen / dimethyl terephthalate molar ratio of 20:1, and a liquid hourly space velocity of 3.0 h⁻¹. -1 Hydrogenation experiments were conducted under the specified conditions, and the reaction results are shown in Table 1. The DMT conversion rate was 99.8%, and the DMCD selectivity was 97.8%.

[0145] Comparative Example 1

[0146] The catalyst in this comparative example does not contain MnO, and is otherwise the same as in Example 1. The resulting catalyst contains 2% Ru, 0.6% Co, and 3% Ca by mass.

[0147] Figure 2 A is a transmission electron microscope (TEM) image of the catalyst prepared in Comparative Example 1, with an average Ru grain size of 4.2 nm.

[0148] 1) Catalyst reduction:

[0149] 10g of catalyst, 20mL of catalyst loading, pure hydrogen gas, reduction at 200℃ for 10h.

[0150] 2) Catalytic hydrogenation:

[0151] Using dimethyl terephthalate solution and pure hydrogen as raw materials, with a catalyst dosage of 10 g, the reaction was carried out at a temperature of 150℃, a reaction pressure of 7.0 MPa, a hydrogen / benzene molar ratio of 30:1, and a liquid hourly space velocity of 3.0 h⁻¹. -1 Hydrogenation experiments were conducted under the specified conditions, and the reaction results are shown in Table 1. The DMT conversion rate was 93.2%, and the DMCD selectivity was 97.5%.

[0152] Comparative Example 2

[0153] The catalyst in this comparative example is the same as the catalyst in Example 1, except that: in the second contact preparation process, after drying, a calcination step of 500°C for 4 hours is added.

[0154] The transmission electron microscope (TEM) images show that the average Ru grain size is 10.5 nm.

[0155] 1) Catalyst reduction:

[0156] 10g of catalyst, 20mL of catalyst loading, pure hydrogen gas, reduction at 200℃ for 10h.

[0157] 2) Catalytic hydrogenation:

[0158] Using dimethyl terephthalate solution and pure hydrogen as raw materials, with a catalyst dosage of 10 g, the reaction was carried out at a temperature of 150℃, a reaction pressure of 7.0 MPa, a hydrogen / dimethyl terephthalate molar ratio of 30:1, and a liquid hourly space velocity of 3.0 h⁻¹. -1 Hydrogenation experiments were conducted under the specified conditions, and the reaction results are shown in Table 1. The DMT conversion rate was 90.4%, and the DMCD selectivity was 95.6%.

[0159] Table 1

[0160]

[0161] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A catalyst for the hydrogenation of terephthalic acid ester to cyclohexane dicarboxylic acid ester, comprising, by weight, the following components: a) 0.1-35 parts of the active ingredient, calculated by element, wherein the active ingredient includes Ru; b) 1-50 parts of the auxiliary component, which, based on elements, includes multiple elements selected from Pd, Cu, Zn, Mn, Co, and Ca; c) 15-98 vectors; in, The main reduction peak of the catalyst in H2-TPR is located at 100-120 °C; The carrier is selected from at least one of alumina, silica, and molecular sieve; In the catalyst, the average particle size of Ru crystals is 2-4 nm.

2. The catalyst according to claim 1, characterized in that, The auxiliary components include multiple of Co, Mn, and Ca.

3. The catalyst according to claim 1, characterized in that, The auxiliary components include Co, Mn, and Ca.

4. The catalyst according to claim 3, characterized in that, The weight ratio of Co, Mn, and Ca, calculated as elements, is (1~4):(3-8):

10.

5. The catalyst according to claim 4, characterized in that, The weight ratio of Co, Mn, and Ca, calculated as elements, is (2~3):(4-6):

10.

6. The catalyst according to claim 1, characterized in that, The content of the active component is 0.2-20 parts by weight; And / or, by weight, the content of the auxiliary component is 2-40 parts; And / or, by weight, the content of the carrier is 40-96 parts.

7. The catalyst according to claim 1, characterized in that, The content of the active component is 0.5-10 parts by weight; And / or, by weight, the content of the auxiliary component is 4-30 parts; And / or, by weight, the content of the carrier is 60-94 parts.

8. The catalyst according to claim 1, characterized in that, The carrier is aluminum oxide.

9. A method for preparing the catalyst for the hydrogenation of p-phenylenedicarboxylic acid ester to cyclohexanedicarboxylic acid ester according to any one of claims 1-8, comprising the following steps: 1) The auxiliary agent source solution and the carrier are brought into initial contact, aged, dried, and calcined to obtain the modified carrier; 2) Add the modified support obtained in step 1) to a Ru-containing solution, then add a precipitant solution for a second contact, age, filter, and dry to obtain the catalyst.

10. The preparation method according to claim 9, characterized in that, In step 2), the final pH value of the second contact system is controlled to be 6.0-8.0; And / or, in step 1), the aging temperature is 15~60 ℃ and the aging time is 1~24h; And / or, in step 2), the aging temperature is 15~50 ℃ and the aging time is 1~24h.

11. The preparation method according to claim 10, characterized in that, In step 2), the final pH value of the second contact system is controlled to be 7.0-8.

0.

12. The preparation method according to claim 9, characterized in that, In step 1), the auxiliary agent source is selected from multiple of H2PdCl4, PdCl2, Cu(NO3)2, Zn(NO3)2, Mn(NO3)2, Co(NO3)2, and Ca(NO3)2; and / or, in step 2), the precipitant is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, and ammonia water; and / or, in step 2), the Ru source in the Ru-containing solution is at least one of ruthenium chloride, ruthenium chloride, and ruthenium chloride salt.

13. The preparation method according to claim 12, characterized in that, In step 1), the auxiliary agent source is selected from multiple of Co(NO3)2, Mn(NO3)2, and Ca(NO3)2.

14. The preparation method according to claim 12, characterized in that, In step 2), the precipitant is selected from potassium hydroxide and / or ammonia; and / or, in step 2), the Ru source in the Ru-containing solution is ruthenium chloride.

15. The preparation method according to claim 9, characterized in that, In step 1), the concentration of the auxiliary agent source solution is 0.1-3.0 mol / L; and / or, in step 2), the concentration of the precipitant solution is 0.1-3.0 mol / L; and / or, in step 2), the concentration of the Ru-containing solution is 0.1-5.0 mol / L.

16. The preparation method according to claim 9, characterized in that, In step 1), the roasting temperature is 300-1000℃ and the roasting time is 2-8h.

17. The preparation method according to claim 16, characterized in that, In step 1), the roasting temperature is 400-800 ℃ and the roasting time is 4-6 h.

18. A method for hydrogenating terephthalic acid ester to cyclohexane dicarboxylic acid ester, comprising reacting terephthalic acid ester with hydrogen gas in the presence of the catalyst described in any one of claims 1-8 to generate cyclohexane dicarboxylic acid ester.

19. The method according to claim 18, characterized in that, The reaction is carried out at a temperature of 100-230 °C, a pressure of 4.0-15.0 MPa, and a liquid hourly space velocity of 0.5-12 h⁻¹. -1 The molar ratio of hydrogen to terephthalic acid ester is 5:1-200:

1.

20. The method according to claim 19, characterized in that, The reaction is carried out at a temperature of 130-200 °C, a pressure of 6.0-13.0 MPa, and a liquid hourly space velocity of 2-8 h⁻¹. -1 The molar ratio of hydrogen to terephthalic acid ester is 20:1-80:1.

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